Seal ring



Dec. 26, 1950 B. w. HUBBARD 2,535,634

SEAL RING Filed April 28, 1949 Patented Dec. 26, 1950 UNITED STATES PATENT OFFICEL 2,535,634 SEAL RINGA Bruce W. Hubbard, Oak Park, Ill.,` assignor to Ideal Roller and Manufacturing Company, Chi-v cago,f Ill... a.` corporation of-A Illinois.

Application April' 28, 19.49,` Serial4 No.901.9.4V

7 Claims. l.

Thisinvention relates to rings of resilient material adapted for radial expansion into engagement with a coacting annular part to form a fiuid tight seal therewith.

The general object is to provide a seal ring of the above character which is reinforced by metal to withstand the severe centrifugally derived stressesV and which at' the same time has a soft cushion-like surface to form a tight fluid seal.

A more detailedi object is to provide a seal ring of thel above character in which a covering of yieldable materialy encloses and is secured effectually to an annulus comprising a helical coil of wire.

The invention also resides in the novel manner of securing the yieldable. covering material to the wire coil.

Other objects and advantages of the invention will become apparent from the following detailedI description taken in connection with the accompanying d-rawings, in which Figure l is an elevational view` of a seal ring embodying thepresent invention.

Fig. 2 is a section taken on the line 2-2 of Fig. 1.

Fig. 3 is a fragmentary elevational view of a part of the uncovered ring.

Fig. 4 is an enlarged fragmentary view of the ring with certain of the parts broken away.

Fig. 5 is a fragmentary View of the tape wrapping.

Generally stated, the improved seal ring comprises a radially expansible base ring Il) and a tubular covering II for the ring completely enclosing each section of the latter and composed of resilient material such as vulcanized relatively yieldable natural or synthetic rubber or elastomeric material such as so-called vinyl plastisols. The wall of the resilient tube is made thicker on the outer periphery of the ring as indicated at IIa so as to provide the desired yieldability of the ring when expanded radially against a coacting annular part (not shown).

Herein, the base ring Il) includes a core I2 in the form of a wire annulus with its ends I4 diaposed substantially in abutment with each other (see Fig. 4). Loosely enclosing the wire l2 is a wire helix I3 wound quite tightly with its opposite end portions wound in overlapping relation as shown in Fig. 3 and secured together as by solder I5, the joint thus formed being located on the side of the ring diametrically opposite from the core ends I4. The ring thus formed is sufficiently rigid to retain a circular shape while being adapted for substantially uniform radial expansion under centrifugal force.

In accordance with the present invention, the

yieldable material forming the tube I I is secured to the base ring in a novel manner such as to preserve the radial expansibility of the ring while avoiding danger of rupturing the covering when the composite ring is rotated at high speed as when the ring is used in a centrifuge. To this end, a layer l5 of material such as flexible plasticA or woven` fabric is interposed between the metal ring I3 and the rubber tube II to which the wrapping becomes bonded integrally during vulcanization of the rubber. The layer IB is formed by wrapping a strip of the material heli'- call-y around the wire coil so as to cover the latter completely. Preferably. the adjacent. convolutions are disposed in edgewise abutting relation as` shown in Fig. 4, thereby making` the covering of minimum. over-all thickness.. for a given thickness of the strip. In this way. the wire coil is. covered completely so as to prevent flowing of rubber in between the adjacent convolutions of. theA wire coil. The ends ll ofthe wrapping strip may overlap each other or be spliced together as desired so as to complete the enclosure of the coil I3 by the wrapping. Before the strip is applied, the coil I3 or the back of the strip or both may be dusted with powdered graphite or the like to prevent adhesion of the fabric to the coil and thus allow freedom of relative movement between the two during expansion and contraction of the ring in service use. The wrapping, although composed of material T which is relatively nonstretchable, will, by virtue of the helical winding of the strip. expand radially with the helical wire coil I3.

It is preferred to employ as the wrapping a finely Woven fabric such, for example, as sooalled airplane cloth and to cut the fabric on the bias as shown in Fig. 5 so that the threads I8 extend generally perpendicular to the coil I3 as shown in Fig. 4 instead of helically. This enables the tape to be laid around the coil smoothly with no danger of wrinkling so as to leave the fabric exposed at any point after application of the relatively thin rubber coating.

After covering of the coil in the manner described above, the wrapping iii is covered with unvulcanized rubber material of the required thickness and composition, supported in a mold of the proper cross-sectional shape, and heated to eifect vulcanization of the rubber which is thus formed into a solid tube II completely en- 3 closing the base ring and integrally united with the fabric Wrapping.

In the seal ring which is completed by vulcanization, the rubber tube i is reinforced by the tubular wrapping I6 and, through the intermediary of the latter, is fastened so securely to the metal base ring ID as to be capable of withstanding extreme centrifugal forces Without danger of disintegration or rupture of the cushion material Il. At the same time, the tubular covering formed by the helical wrapping i6 and the rubber Il is adapted to expand and contract radially with the base ring ill. By covering the coil I3 with an impervious Wrapping, the soft outer sealing cushion l l@L is formed Without nowing of any rubber into the coil I3, the expansibility of the latter being thereby preserved.

This application is a continuation-in-part of my copending application Serial No. 732,468, filed March 5, 1947, now abandoned.

I claim as my invention :l i

1. A seal ring comprising a helically Wound coil of wire with its ends interlocking with each said annulus to completely cover all parts of the latter While being radially expansible with the annulus, and an integral sleeve of molded resilient material covering said wrapping and .bonded thereto.

2. A seal ring comprising a helically Wound coil of wire With its ends interlocking with each ,other to form a radially expansible and contractible annulus, a strip of fabric wrapped helically around said annulus to completely cover all parts of the latter While being radially eX- pansible and contractible with the annulus, and an integral sleeve of molded resilient material covering said wrapping and bonded thereto.

3. A seal ring comprising a helically wound coil of Wire connected at its end and forming a radially expansible and contractible annulus,

a tape wrapped helically around said annulus to completely cover all parts of the latter While being radially expansible and contractible with the annulus, and an integral sleeve of molded resilient material covering said Wrapping and bonded thereto.

4. A seal ring comprising a helically Wound coil of wire with its ends connected together to form a radially eXpansible and contractible annulus, a Woven fabric tape wrapped helically around said annulus to completely cover all parts of the latter, the fabric of said tape being cut on the bias so that the threads thereof extend diagonally across the tape and substantially radially around said coil, and an integral sleeve of molded resilient material covering said Wrapping and bonded thereto.

5. A seal ring comprising a helically wound coil of Wire with its ends connected together to form a radially expansible and contractible annulus, a woven fabric tape wrapped helically around said annulus to completely cover all parts of the latter, the fabric of said tape being cut on the bias so that the threads thereof extend diagonally across the tape, and an integral sleeve o molded resilient material covering said Wrapping and bonded thereto.

6. A seal ring as defined by claim 3 in which said tape is an impervious fabric material.

7. A seal ring as dened by claim 3 in which said tape is a fabric separated from the surface of said coil by a coating of powdered material.

BRUCE W. HUBBARD.

REFERENCES CITED The following references are of record in the lile of this patent:

UNITED STATES PATENTS Number Name Date 249,560 Van Wagenen Nov. l5, 1881 404,913 Johns June 1l, 1889 1,826,092 Rice Oct. 6, 1931 2,235,523 Hull Mar. 18, 1941 

